If you are to look further, natural resources doesn’t make much larger share in Russian than it is in US economy. I might be mistaking but IMHO it is around 15% for either.
On the other hand, oil and gas industries are taxed heavier than other businesses, let alone individuals in Russia and that is why oil brings the most revenues for a government.
But this seems fair, as the Russian government has been helping the gas industry build pipelines into neighboring countries and such. You can bet your bottom dollar something like Keystone would be a no-brainer for Putin.